His head really does look like his suit is trying to take a very messy shit through its neck hole.

I believe the three motor versions is to add extra power under load to the rear wheels. (A weight/power/range compromise between the 4 and 2 motor versions).

The motors are essentially in line with the wheels (they have gearing but it’s minimal and internal to the motor housing, not attached like an automatic transmission would be, if that makes sense.)

The “three motor” design is just the single motor design up front and the dual motor design in the back.

I’m not sure if they ever actually released the single motor version though.